Wavetek ANT-20 User manual

BN 3060/98.38
ANT-20SE
Advanced Network Tester
ANT-20 NEXT
Network Expert Test Software
BN 3035/95.40
Software Version 2.00
Operating Manual
9

Please direct all enquiries to your
local Wavetek Wandel Goltermann sales
company. The addresses are
given at the end of this handbook.
Copyrights
This product or parts of it are based upon
Recommendations and/or Standards of the
Standardization Sector of the International
Telecommunication Union - ITU-T and/or of the
European Telecommunications Standards Institute -
ETSI. These Recommendations and Standards are
subject to copyrights of these organizations. Without
written permission of the ITU-T and/or ETSI it is not
permitted to copy ITU-T Recommendations or ETSI
standards or parts thereof and/or make them available
to third parties.
Wavetek Wandel Goltermann
Eningen GmbH & Co.
Mühleweg 5, 72800 Eningen u. A.
© 2000
Author: MDD/TD
Translator: John Nutley
Order no.: BN 3035/98.38
Edition: 01/00.04 (V 2.00)
Subject to change without notice.
Our normal guarantee and delivery
terms apply.
Printed in Germany

ANT-20SE ANT-20 NEXT
i
Contents
Introduction
1 ANT-20 NEXT software. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .I-1
2 About this operating manual. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .I-2
Getting started
1 Installing the ANT-20 NEXT software . . . . . . . . . . . . . . . . . . . . . . . .G-1
2 Backup. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .G-3
Standard Applications
1 Overview of standard applications. . . . . . . . . . . . . . . . . . . . . . . . .SA-1
2 Basic information on running applications . . . . . . . . . . . . . . . . . .SA-2
2.1 Measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .SA-2
2.1.1 Typifying line parameters . . . . . . . . . . . . . . . . . . . . . . . . . .SA-2
2.1.2 Performing optional measurements . . . . . . . . . . . . . . . . . .SA-4
3 Applications for 2 Mbit/s signals . . . . . . . . . . . . . . . . . . . . . . . . . .SA-5
3.1 Monitoring 2 Mb/s, full check (approx. 25 min) . . . . . . . . . .SA-5
3.2 Line 2 Mb/s, unknown structure . . . . . . . . . . . . . . . . . . . . .SA-7
3.3 Line 2 Mb/s, PCM31CRC, terminated & re-timing,
full test (approx. 25 min) . . . . . . . . . . . . . . . . . . . . . . . . . . .SA-9
3.4 Line 2 Mb/s, transparent (unframed), no re-timing,
full test (approx. 25 min) . . . . . . . . . . . . . . . . . . . . . . . . . .SA-11
4 Applications for 34 Mbit/s signals . . . . . . . . . . . . . . . . . . . . . . . .SA-13
4.1 Monitoring 34 Mb/s, full check (approx. 25 min) . . . . . . . .SA-13
4.2 Line 34 Mb/s, unknown structure . . . . . . . . . . . . . . . . . . .SA-15
4.3 Line 34 Mb/s, transparent (unframed),
full test (approx. 25 min) . . . . . . . . . . . . . . . . . . . . . . . . . .SA-17
5 Applications for STM-1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .SA-19
5.1 Monitoring STM-1, full test (approx. 25 min). . . . . . . . . . .SA-19
5.2 Line STM-1, unknown structure . . . . . . . . . . . . . . . . . . . .SA-21

ANT-20 NEXT ANT-20SE
ii
5.3 Line STM-1 VC-4, full check (approx. 25 min) . . . . . . . . .SA-23
5.4 Line STM-1, Digital Radio, full check (approx. 25 min). . .SA-25
Operating
1 For users in a hurry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .O-1
1.1 Connecting the items under test. . . . . . . . . . . . . . . . . . . . . .O-1
1.2 Starting the ANT-20 NEXT software. . . . . . . . . . . . . . . . . . .O-2
1.3 Evaluating and recording the diagnosis . . . . . . . . . . . . . . . .O-8
2 For advanced users . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .O-9
2.1 Starting the software. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .O-9
2.1.1 Starting the software from the Start menu . . . . . . . . . . . . . .O-9
2.1.2 Starting the software from a desktop icon. . . . . . . . . . . . . . .O-9
2.2 Loading an application . . . . . . . . . . . . . . . . . . . . . . . . . . . .O-10
2.2.1 Automatically loading the last application selected. . . . . . .O-10
2.2.2 Loading an application with the Load button. . . . . . . . . . . .O-10
2.2.3 Loading an application with the Load menu item in the
Application menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .O-11
2.2.4 Opening one of the last five applications loaded . . . . . . . .O-11
2.2.5 Creating a new icon (shortcut) . . . . . . . . . . . . . . . . . . . . . .O-12
2.3 Starting the diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . .O-13
2.4 Aborting a diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .O-14
2.5 Reporting the results. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .O-15
2.5.1 Viewing the report. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .O-15
2.5.1.1 Report structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .O-16
2.5.2 Saving the report. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .O-19
2.5.3 Loading a report . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .O-20
2.5.4 Printing the report . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .O-20
2.5.5 Adding a logo to the report . . . . . . . . . . . . . . . . . . . . . . . . .O-20
2.6 Creating and customizing applications . . . . . . . . . . . . . . . . O-21
2.6.1 Creating a new application . . . . . . . . . . . . . . . . . . . . . . . . .O-21
2.6.2 Customizing an application. . . . . . . . . . . . . . . . . . . . . . . . .O-22
2.6.3 Saving a (new) application . . . . . . . . . . . . . . . . . . . . . . . . .O-28
2.6.4 Saving an (edited) application. . . . . . . . . . . . . . . . . . . . . . .O-28

ANT-20SE ANT-20 NEXT
Introduction I-1
Introduction
1 ANT-20 NEXT software
The “ANT-20 NEXT” software (ANT-20 Network Expert Test) makes it easy for even
inexperienced users to commission or troubleshoot communications lines. The “ANT-20 NEXT”
software can be run as an alternative to the standard graphical user interface of the ANT-20.
All you need to do to perform a measurement is select the type of path to be tested. All the
important measurements for characterizing and quality analysis of the path are then performed
automatically.
If the item under test is of unknown type, you can perform a “type determination” test, which
determines all the properties of the item under test and lists them in a comprehensive report.
The “ANT-20 NEXT” software provides individual information about possible error causes and
tips on how to clear the fault if problems or faults occur with the item under test or in the cabling.
Because the possible error causes usually depend on the item under test, you can add your
own descriptions and notes to an existing “knowledge database”. The result is a complete,
individually-tailored test system based on your level of experience. You can specify the scope
of tests, the limit values that must be met and the expected values for, say, an alarm sensor test
covering every existing type of device under test or measurement setup. These customized test
applications can be saved and are then available at the click of a button the next time you use
the “ANT-20 NEXT” software.

ANT-20 NEXT ANT-20SE
I-2 Introduction
2 About this operating manual
Overview
Chapter Contents
“Getting started” •This chapter describes how to start using the “ANT-20 NEXT” software on the
ANT-20.
“Standard
Applications” •This chapter contains an overview of the pre-defined applications, separated into 2 Mbit/s signals and STM-1 signals:
– Monitoring an unknown 2 Mbit/s signal
– Analysis of a 2 Mbit/s line with unknown properties
– Commissioning a structured 2 Mbit/s communications line
– Commissioning a transparent 2 Mbit/s communications line
– Monitoring an unknown 34 Mbit/s signal
– Analysis of a 34 Mbit/s line with unknown properties
– Commissioning a transparent 34 Mbit/s communications line
– Monitoring/Analysis of unknown STM-1 SDH signals
– Analysis of unknown STM-1 lines
– Commissioning of STM-1 VC-4 communications lines
– Commissioning STM-1 radio links
“Operating” •This chapter is divided into two sections:
– Section 1 “For users in a hurry” describes how you can quickly start the
“ANT-20 NEXT” software and perform one of the pre-defined test
applications.
– Section 2 “For advanced users” describes operation in detail, particularly
how to customize the standard applications to meet your specific
requirements.
Table I-1 Operating manual contents

ANT-20SE ANT-20 NEXT
Getting started G-1
Getting started
1 Installing the ANT-20 NEXT software
If the “ANT-20 NEXT” software has not been installed on your ANT-20 yet, you can use the
installation disks to install the software yourself.
To install the “ANT-20 NEXT” software
✓The ANT-20 is switched on.
✓All applications have been closed.
1. Insert the first installation disk into drive A.
2. Click on “Run” in the Start menu.
The “Run” window opens.
3. Type in “a:\setup.exe” in the text box.
4. Click on “OK”.
The “ANT-20 NEXT” software will be installed.
5. Follow the instructions given by the installation program.
Note: If possible, do not change the directory structure suggested by the installation program.
When installation is complete the Start menu will contain the menu item “ANT-20 NEXT/
ANT-20 NEXT” under “Programs”.
Fig. G-1 Start menu with “ANT-20 NEXT” software menu item

ANT-20 NEXT ANT-20SE
G-2 Getting started
A new program group with the following icon is also displayed:
Fig. G-2 “ANT-20 NEXT” software icon
Copying icons (shortcuts) to the desktop
⇒Copy these icons to the ANT-20 desktop.
You can start the “ANT-20 NEXT” software at any time by clicking on them.
Enabling the software
If you install the “ANT-20 NEXT” software on your ANT-20 yourself, you will need to enter the
access code supplied with the software when you start the software for the first time. The dialog
window for entering the access code will not be displayed the next time that you start the
“ANT-20 NEXT” software.
The access code is supplied on a separate sheet included with the set of floppy disks. It has the
format: “3035/95.40:XYZW”. You only need to enter the last four characters.

ANT-20SE ANT-20 NEXT
Getting started G-3
2 Backup
The “ANT-20 NEXT” software is stored in the following directories on the hard disk of the
ANT-20:
Fig. G-3 Directory structure
You can generate or change the following files:
•Report files containing measurement results
(file name extensions: *.htc, *.htm, *.htr, *.hts)
•GIF files with company logos
(file name extension: *.gif)
•Text or HTML files that contain additions to the “knowledge database”
(file name extensions: *.htm or *.txt).
•User-specific applications
(file name extensions: *.p1 for 2 Mbit/s applications, *.p3 for 34 Mbit/s applications or *.p2 for
STM-1 applications)
The result files are stored in the “C:\ANT_NEXT\REPORT” directory by default. Changes in the
“knowledge database” and the user-specific applications are stored in either the
“C:\ANT_NEXT\APPL\...” directory.
Caution
Loss of data
Data can be lost if the hard disk is damaged.
⇒Make regular backup copies of your data and files on external data media.

ANT-20 NEXT ANT-20SE
G-4 Getting started
Notes:

ANT-20SE ANT-20 NEXT
Standard Applications SA-1
Standard Applications
1 Overview of standard applications
The standard applications are divided into three main groups:
•Applications for 2 Mbit/s signals
•Applications for 34 Mbit/s signals
•Applications for STM-1 signals
Each main group is linked to a separate “knowledge database”. The “knowledge database”
contains information regarding error causes. You can add to and edit this information. Refer to
Section 2.6 “Creating and customizing applications”,Page O-21 for details of how to do this.
Application name Notes
Applications for 2 Mbit/s signals
Monitoring 2 Mb/s,fullcheck(approx.
25 min) Monitoring an unknown 2 Mbit/s signal Page SA-5
Line 2 Mb/s, unknown structure Analysis of a 2 Mbit/s line with unknown
properties Page SA-7
Line 2 Mb/s, PCM31CRC, terminated
& re-timing, full test (approx. 25 min) Commissioning a structured 2 Mbit/s communications line Page SA-9
Line 2 Mb/s, transparent (unframed),
no re-timing, full test (approx. 25 min) Commissioning a transparent 2 Mbit/s communications line Page SA-11
Applications for 34 Mbit/s signals
Monitoring 34 Mb/s, full check
(approx. 25 min) Monitoring an unknown 34 Mbit/s signal Page SA-13
Line 34 Mb/s, unknown structure Analysis of a 34 Mbit/s line with unknown
properties Page SA-15
Line 34 Mb/s, transparent
(unframed), full test (approx. 25 min) Commissioning a transparent 34 Mbit/s communications line Page SA-17
Applications for STM-1 signals
Monitoring STM-1, full test (approx.
25 min) Monitoring/Analysis of unknown STM-1 SDH signals Page SA-19
Line STM-1, unknown structure Analysis of unknown STM-1 lines Page SA-21
Line STM-1VC-4, full check (approx.
25 min) Commissioning of STM-1 VC-4 communications lines Page SA-23
Line STM-1, Digital Radio, full check
(approx. 25 min) Commissioning STM-1 radio links Page SA-25
Table SA-1 Overview of standard applications
Note: How to start the “ANT-20 NEXT” software, load an application and perform a
diagnosis is described in the “Operating” Chapter:
•Section 1 “For users in a hurry”,Page O-1
•Section 2 “For advanced users”,Page O-9

ANT-20 NEXT ANT-20SE
SA-2 Standard Applications
2 Basic information on running applications
2.1 Measurement
There are two basic types of measurement:
•Monitoring (only involves ANT-20 RX)
•Line measurement with loop back at far end (involves TX and RX)
Each measurement takes place in two stages:
•Setting up the ANT-20 and determining the type of item under test
•Performing optional quality measurements such as long-term BERT, G.826/M.2100, intrinsic
jitter test, MTJ, etc.
The generator section of the ANT-20 is not involved when the device is set for “Monitoring”. The
item under test is typified using the received signal only. It is not possible to check whether the
path being measured is clock or pattern transparent. It is also not possible to perform tolerance
to jitter measurements and alarm sensor tests.
2.1.1 Typifying line parameters
Inputs and outputs
The ANT-20 automatically sets the correct TX outputs and RX inputs (balanced, coaxial or
optical) during the first stage. This eliminates one of the most common causes of error in
manual measurements.
If the selected application allows measurements on PMP levels or measurements using the
built-in equalizer of the ANT-20, these parameters will also be automatically set to their optimum
settings.
Once the correct RX settings and a corresponding TX setting have been found for the ANT-20,
a check is made to determine if the line is looped back at the far end. The program determines
if the data transmitted by the ANT-20 generator can be transmitted to the ANT-20 generator.
Frame structure
The “ANT-20 NEXT” software automatically sets PCM31 or PCM31CRC frames for those line
types where these frames are expected. An unframed signal is used for all subsequent
measurements if it is detected that the line is transparent to signal structure.
Clock type
The clock type is an important criterion for typifying a 2 Mbit/s communications line.
A basic distinction is made between “clock-transparent” and “re-timing”.
The “ANT-20 NEXT” software first determines the type of line. The ANT-20 is then automatically
set correctly for subsequent measurements.
To determine the line type, the TX signal of the ANT-20 (setting: TX clock internal) is offset by
10 ppm and the received clock signal measured.
If the received clock is also offset by 10 ppm, the line is “clock-transparent”.
If no offset is present in the received clock signal, the line operates with “re-timing”.

ANT-20SE ANT-20 NEXT
Standard Applications SA-3
If the line is “clock-transparent”
The transmission path accepts an externally superimposed clock signal and transmits it
unchanged.
If the line is “clock-transparent”, the internal clock of the ANT-20 will be used. A separate
measurement of the “clock pulling range” is performed during the diagnosis to establish whether
the line also performs correctly at the limits of the pulling range.
If the line is operated with “re-timing”
The line uses its own clock signal regardless of the incoming signal clock.
If the line operates with “re-timing”, the ANT-20 is automatically set to “Clock from RX”. This
ensures that the line clock and the clock signal transmitted by the ANT-20 are identical.
This setting avoids sporadic bit slips (ANT-20: LSS) that occur as a result of slight differences in
the two clock signals.
Measurement of the clock pulling range is unnecessary, since the clock is set by the item under
test.
Checking known line properties
If the desired or required properties of the line to be tested are known (transparent or structured
lines), a check is first made to see if these properties are present. The in-depth measurements
(e.g. MTJ, G.826, jitter) are performed after this.
Note: The “ANT-20 NEXT” software sets itself automatically to the line type detected and
performs all relevant measurements.
Example:
During commissioning of an “unstructured line”, the “ANT-20 NEXT” software determines that
the line is, in fact, structured.
This leads to the “ANT-20 NEXT” software producing the diagnosis “Framed” which is
evaluated as an error. Subsequent measurements are based on the knowledge that the line is
structured. The alarm sensor tests such as LOS →RDI, which have no meaning for an
unstructured line, are therefore performed.

ANT-20 NEXT ANT-20SE
SA-4 Standard Applications
2.1.2 Performing optional measurements
Once the line has been typified completely, you can make further measurements to test the line
quality according to the selected application.
The following measurements can be performed (using 2 Mb/s as example):
•Alarm sensor tests for pattern-transparent lines:
–LOS→AIS_2 M
•Alarm sensor and error sensor tests for framed lines:
–LOS→AIS_64k
–LOF→AIS_64K
–LOF→RDI (“Remote Defect”/D bit/remote alarm triggered on loss of frame)
– FAS error rate >1E-3 →RDI
– RDI →RDI (transparency test for a “Remote Defect”)
– CRC-4 errors →E bits
•Intrinsic jitter at the output of the item under test
•Tolerance to jitter of the item under test
•Clock pulling range (for clock-transparent systems only)
•G.826/M.2100 long-term quality monitoring

ANT-20SE ANT-20 NEXT
Standard Applications SA-5
3 Applications for 2 Mbit/s signals
Most of the applications described in the following sections are also available as “quick check”
versions.
3.1 Monitoring 2 Mb/s, full check (approx. 25 min)
Monitoring an unknown 2 Mbit/s signal
Fig. SA-1 Monitoring an unknown 2 Mbit/s signal
Connecting the item under test
The balanced or coaxial sockets of the item under test are connected to input [12] or [14] of the
receiver for the “Monitoring 2 Mb/s, full check (approx. 25 min)” application.
Tip: If the item under test is not equipped with a PMP socket, you can connect the ANT-20 to
a “hot” line using a probe (e.g. TKD-1 from Wavetek Wandel Goltermann).
Measurement
The application automatically detects the correct impedance and receive level (ITU-T or PMP)
and starts the line type test. This determines the type of signal present at the receiver input:
•PCM31
•PCM31CRC
•Unframed
•AIS_2M
•Unknown (if none of the above signal types could be clearly determined, e.g. because a
different bit rate was present)
The clock frequency deviation of the incoming signal is measured. The measured value will be
displayed if it is more than ±2 ppm.

ANT-20 NEXT ANT-20SE
SA-6 Standard Applications
If widely differing values are measured during three consecutive measurements, the diagnosis
“Clock variable” is given. A diagnosis of “Clock variable” is an indication of synchronization
problems. It may also indicate that a signal with a different bit rate or with a line code that does
not correspond to HDB3 is present.
If a framed signal is detected, the current alarm situation will also be displayed:
•RDI (remote alarm, D bit)
•AIS_64k (i.e. framed signal with all ones in all payload channels)
Optional measurements
The following optional measurements allow further analysis of the quality of the incoming signal:
•Intrinsic jitter
•G.826 analysis for a period of 15 minutes
– Analysis is referred to the FAS or CRC/E bit for framed signals with unknown payload (in-
service).
– Analysis is referred to the payload if a “PRBS15 payload” or “framed pattern PRBS15” is
detected for unframed or PCM31CRC signals (out of service).
Alarms and error messages
If alarms occur or limit values are exceeded, a brief explanatory text is displayed in the “Possible
Causes” field of the “ANT-20 NEXT - [Application]” window. A more detailed cause description
and further information can be displayed if you double-click on the item of interest and the
necessary information is stored in the “knowledge database”. You can add to or edit the texts
stored in the “knowledge database”.
Also refer to Section 2.6.2 “Customizing an application”,Page O-22 for more information.
Adaptations
You can adapt the “Monitoring 2 Mb/s, full check (approx. 25 min)” application to suit your
special requirements. This applies to the jitter and G.826 tests in particular. You can also
change the limit values and gate times.
Also refer to Section 2.6 “Creating and customizing applications”,Page O-21 for more
information.

ANT-20SE ANT-20 NEXT
Standard Applications SA-7
3.2 Line 2 Mb/s, unknown structure
Analysis of a 2 Mbit/s line with unknown properties
Fig. SA-2 Analysis of a 2 Mbit/s line with unknown properties
Special features
If the properties of the line are unknown, a measurement to determine the type of line present
is performed first. After this, measurements that apply to the type of line detected will be
performed.
A “Pass/Fail” assessment will not be made from the properties that are detected, since the
nominal line type is unknown.
Connecting the item under test
The balanced or coaxial output and input sockets of the item under test are connected to input
[12] or [14] of the receiver (RX) and output [13] or [15] of the generator (TX) for the
“Line 2 Mb/s, unknown structure” application.
Measurement
The application initially starts a measurement to typify the line. The following properties of the
line are investigated:
•Is the line also suitable for unframed signals (transparent)?
•Is the line only suitable for framed (structured) PCM31or PCM31CRC signals (Framed,
CRC-4)?
•Does the line transmit the received signal without imposing its own clock signal, i.e. is the
line clock-transparent (re-timing)?
•Is there a loop back for the payload data at the far end of the line (continuity)?
•Is the line terminated for FAS?
After this, measurements that apply to the type of line detected will be performed:
•Do the alarm and error sensors work properly?
•Is the frequency of the incoming signal (when there is no RX signal) within ±2 ppm of the
nominal clock frequency (AIS frequency)?
•Are the intrinsic jitter and tolerance to jitter within the limit values?
•Does a clock-transparent line also operate properly at the limits of the clock pulling range?
•Are any errors detected during a G.826 / M.2100 analysis (long term measurement)?

ANT-20 NEXT ANT-20SE
SA-8 Standard Applications
Alarms and error messages
If alarms occur or limit values are exceeded, a brief explanatory text is displayed in the “Possible
Causes” field of the “ANT-20 NEXT - [Application]” window. A more detailed cause description
and further information can be displayed if you double-click on the item of interest and the
necessary information is stored in the “knowledge database”. You can add to or edit the texts
stored in the “knowledge database”.
Also refer to Section 2.6.2 “Customizing an application”,Page O-22 for more information.
Adaptations
You can adapt the “Line 2 Mb/s, unknown structure” application to suit your special
requirements. This applies to the jitter and G.826 tests in particular. You can also change the
limit values and gate times.
Also refer to Section 2.6 “Creating and customizing applications”,Page O-21 for more
information.

ANT-20SE ANT-20 NEXT
Standard Applications SA-9
3.3 Line 2 Mb/s, PCM31CRC, terminated & re-timing, full test (approx. 25 min)
Commissioning a structured 2 Mbit/s communications line
Use the “Line 2 Mb/s, PCM31CRC, terminated & re-timing, full test (approx. 25 min)” application
if you intend to commission a structured and terminated 2 Mbit/s PCM31CRC line.
Special features
If the desired or required properties of the line to be tested are known (transparent or structured
lines), a check is first made to see if these properties are present. The in-depth measurements
(e.g. MTJ, G.826, jitter) are performed after this.
Connecting the item under test
The balanced or coaxial output and input sockets of the item under test are connected to input
[12] or [14] of the receiver (RX) and output [13] or [15] of the generator (TX) for the “Line 2 Mb/
s, PCM31CRC, terminated & re-timing, full test (approx. 25 min)” application.
Measurement
The following typical line parameters are expected:
Note: The clock pulling range is not measured, since “re-timing” is used. All measurements
are performed with the “ANT-20 TX clock from RX” setting.
The following measurements are then performed:
Typical line parameter Explanation
Frames Yes
CRC Yes
Re-timing Yes
Termination for FAS and CRC FAS and CRC errors are not returned to the ANT-20 via the loop
back.
CRC-4 / E bit detection Every inserted CRC-4 error must be acknowledged by an E bit
error.
Table SA-2 Expected line type parameters
Test Explanation
Alarm sensor test LOS →AIS_64k The line must return aframedall ones signal if no signal is present
at the input.
Alarm sensor test LOS →RDI The line must return a RDI (D bit) if no signal is present at the
input.
Alarm sensor test RDI →RDI RDI must pass through transparently.
Signal delay < 22 ms “round trip” Corresponds to an “end-to-end” delay of 11 ms
Intrinsic jitter HP1 (10 Hz/100 kHz):
< 1.1 UIpp Intrinsic jitter measured with HP1 (10 Hz high-pass filter)
Table SA-3 Measurements performed

ANT-20 NEXT ANT-20SE
SA-10 Standard Applications
Alarms and error messages
If alarms occur or limit values are exceeded, a brief explanatory text is displayed in the “Possible
Causes” field of the “ANT-20 NEXT - [Application]” window. A more detailed cause description
and further information can be displayed if you double-click on the item of interest and the
necessary information is stored in the “knowledge database”. You can add to or edit the texts
stored in the “knowledge database”.
Also refer to Section 2.6.2 “Customizing an application”,Page O-22 for more information.
Adaptations
You can adapt the “Line 2 Mb/s, PCM31CRC, terminated & re-timing, full test (approx. 25 min)”
application to suit your special requirements. This applies in particular to the jitter and G.826
tests and also to the “re-timing” property that is either expected or to be eliminated. You can also
change the limit values and gate times.
Also refer to Section 2.6 “Creating and customizing applications”,Page O-21 for more
information.
Intrinsicjitter HP2 (18kHz/100 kHz):
< 0.2 UIpp Intrinsic jitter measured with HP2 (18 kHz high-pass filter)
MTJ The requirements of ITU-T G.823 must be met.
M.2100/G.826 No errors may occur for measurement times of up to 24 hours.
Test signal: PCM31CRC with PRBS15
A G.826“Out of Service” analysisis performed (defaultgate time:
15 min).
Test Explanation
Table SA-3 Measurements performed
(continued)